async function f() {
  console.log('start--------')
  let a = await af()
  let b = await bf()
  console.log('a:'+a)
  console.log('b:'+b)
  console.log('over--------')
}


function af() {
  console.log('aaaaaaaaa')
  return '111'
}

function bf() {
  console.log('bbbbbbbbbb')
  return '222'
}

f()